Stellera chamaejasme induced apoptosis of HL-60 cells and regulated expression of bcl-2 protein in SGC-7901 cells

Object To explore the antitumor mechanism of Stellera chamaejasme Linn. (SC). Methods SC containing-serum (SCCS) was derived from mice pretreated with different doses of SC. Cultured human leukemia HL-60 and human gastric adenocarcinoma SGC-7901 cells were used. Inhibition of proliferation was measured using MTT assay. Morphological assessment of apoptosis was performed with fluorescence microscope. DNA fragmentation was assessed by agarose gel electrophoresis and flow cytometry. Expression of bcl-2 protein was measured with immunohistochemistry. Results Exposure of exponentially growing HL-60 cells to mice serum containing 10% SC (pretreated with SC 3, 6, and 12 g/kg) for 48 h resulted in growth inhibition in a dose-dependent manner. Typical morphological changes of apoptosis and DNA fragmentation in HL-60 cells were induced. Apobodies in the apoptotic cells were observed, ladder pattern of agarose gel electrophoresis of DNA from these cells was revealed, and the percentage of apoptotic cells with fractional DNA content increased from 11.7% to 57.4%. Treatment with SC containing serum decreased the percentage of SGC-7901 cells of bcl-2 protein positive expression from 78.3% to 32.9%. Conclusion SC could induce apoptosis of HL-60 cells and decrease the expression of bcl-2 protein of gastric adenocarcinoma SGC-7901 cells.